Valid Feed but No feed items found – other feeds work fine

Hello,

Thank you for the free version of this plugin. I use it and want to upgrade to Pro Plan.

I get “No feed items found.” but other feeds work well.

I want to upgrade to your $149 annual Pro Plan but need to solve the above because I want to curate posts with your Feed to Post and Full Text RSS Feeds add-ons.

The feed that fails to import (on the feed settings page and on the home page) is
https://blog.nexcess.net/

But, the feed validates.
Congratulations! [Valid RSS] This is a valid RSS feed.
https://validator.w3.org/feed/check.cgi?url=https%3A%2F%2Fblog.nexcess.net%2F

However, I notice that when it validates the feed URL changes to a feedburner URL
https://feeds.feedburner.com/nexcess

It is critical for this site that the feed can be imported as well as 100% use your Feed to Post and Full Text RSS Feeds add-ons.

Thank you for your help.

Chris